A 2026 guide to rent reviews, Form 4A and market-rent evidence There is no fixed percentage cap for an ordinary private-sector rent increase in England. A landlord cannot simply decide that 5%, 10% or any other figure is automatically acceptable. The central test is whether the proposed rent is defensible against the open-market rent for that property, on those tenancy terms, in that local market. Since 1 May 2026, the operational discipline around rent reviews has become mor